No. She could 'work in law' in the same way in New Jersey as she could in Greece - as a 'jurist' or 'company lawyer', but not initiate court proceeding. Being admitted to the bar in one Member State does not automatically mean admittance to the bar in another Member State, nor does it even mean that one is eligible to just take the bar exam in that other Member State (although this last part is under proceedings before the European Court for restricting movement of persons within the Union.

In contrast, one doesn't even need a law school degree to be able to take the bar exam in any US state. (admittedly it's almost impossible to pass without one).

> one doesn't even need a law school degree to be able to take the bar exam in any US state

Not quite: In a number of US states, a prerequisite to taking the bar exam is either graduation from an ABA-accredited law school, or a foreign law degree with additional training in a U.S. school. See Chart III at http://www.ncbex.org/fileadmin/mediafiles/downloads/Comp_Gui... and the supplemental remarks afterwards, also Chart X.

I stand corrected, thank you.

Not as a qualified lawyer she couldn't - even within the UK there are different legal systems that require you to qualify separately. There is a lot more to being a lawyer/solicitor than getting a law degree. (e.g. Here in Scotland it is a further post graduate qualification plus two years training in a law firm before you qualify).